Books Books All the interior angles of any rectilineal figure, together with four right angles, are equal to twice as many right angles as the figure has sides. A Course of Mathematics ...: Composed for the Use of the Royal Military ... - Page 64
by Charles Hutton - 1811 ## Mathematics, mechanics, heat

...ABCDEF oe the given polygon. To prove that the sum of the interior angles A, B, C, D, E, and F, is equal to twice as many right angles as the figure has sides minus two. If from any vertex as A, diagonals AC, AD, AE, are drawn, the polygon will be divided into... ## The Colliery Manager's Handbook

Caleb Pamely - 1904
...for, " The sum of all the interior angles of any rectilinear figure, together with 4 right angles, are equal to twice as many right angles as the figure has sides." This is not so thorough a test as the plotting, because it checks only the angles taken and not the... ## A Treatise on Surveying, Volume 1

...angles as the figure has sides. The sum of the ' exterior ' angles diminished by four right angles is equal to twice as many right angles as the figure has sides. The sum of the ' differences of latitude ' being ' northings,' is equal to the sum of those which are... ## Introduction to Geometry: A Manual of Exercises for Beginners

William Schoch - Geometry - 1904 - 137 pages
...of a polygon without measuring them ? Exercise 33. If the sum of the interior angles of a polygon is equal to twice as many right angles as the figure has sides less four right angles, determine the sum of the interior angles of : 1. A six-sided polygon, or hexagon.... ## A Text-book of Euclid's Elements for the Use of Schools, Book 1

Euclid - Euclid's Elements - 1904 - 456 pages
...right angles as the figure has sides. But all the interior angles, with four right angles, are together equal to twice as many right angles as the figure has sides. I. 32, Cor. 1. Therefore all the interior angles, with all the exterior angles, are together equal... ## Text Book of Topographical and Geographical Surveying

Sir Charles Frederick Close, Sir Charles Frederick Arden-Close - Surveying - 1905 - 288 pages
...traverse together with the line AB form an enclosed figure, and the sum of all the interior angles should be equal to twice as many right angles as the figure has sides, less four right angles. We thus have a check on the observed horizontal angles. It should be carefully... ## Catalogue ...

...altitude is 3 in. PLANE GEOMETRY SEPTEMBER, 1909 1. The sum of all the interior angles of any polygon is equal to twice as many right angles as the figure has sides, less four right angles. 2. The angle between two chords which intersect within a circle is measured... ## A Text-book of Engineering Drawing and Design: Practical geometry

...which says, that " the interior angles of any straight lined figure together with four right angles are equal to twice as many right angles as the figure has sides." The most common of the regular polygons used in engineering designs are the pentagon (five-sided),... ## Hints to Travellers: Scientific and General, Volume 1

...traverse together with the line AB form an enclosed figure, then the sum of all the interior angles should be equal to twice as many right angles as the figure has sides, less four right angles. We thus have a check on the observed horizontal angles. It should be carefully... 